rearrange string with mixed languages (LTR + RTL)?

I have a text with mixed languages, (one LTR and the other 开发者_运维技巧RTL).when sending the string on SMTP the string gets mixed up .Is there any way to recognize the string ?

RTL only affects the display of text, not the transmission. Not sure what "mixed up" might mean but I'd recommend you take a good look at the MailMessage.BodyEncoding property. The default is ASCII, not suitable for sending the kind of characters used in a RTL language. If that doesn't help then consider that the problem might actually be caused by the mail reader you are using. It might not support RTL or cannot handle a mix.